The instant invention relates to a method of forming a fusion nib on a part in a progressive die system, and more particularly to a method of forming a fusion nib on a stamped backing for a jewelry article.
In many industries, and particularly in the jewelry industry, it has become desirable to attach parts together using a fusion process rather than a soldering process. The fusion process provides a much stronger connection than soldering and is more easily automated than soldering, thus leading to a better quality lower cost product. The advantages of widespread use of such technology are obvious from a business standpoint.
Generally speaking, fusion is accomplished by applying a low voltage, high amperage current between two adjacent parts. The electrical current arcs and welds the parts together using local material from each of the parts as working material. In carrying out these processes, it has been discovered that it is advisable to form a fusion nib, i.e. a small bump or protrusion, on one of the parts to be fused. The nib acts to provide some of the local working material for the weld and may also act as a registration point for aligning a mating part having either a recess or an aperture.
In industries where the fused parts are larger and easy to work with, the fusion nib can be formed by casting methods or other conventional machining methods. However, in the jewelry industry, where the parts are usually small, it has been difficult, if not impossible, to form a fusion nib by conventional casting and machining methods. Accordingly, the widespread use of fusion technology has not yet occurred in the jewelry industry, or in other industries where the working parts are small.
The instant invention provides an improved method of forming a fusion nib on a part using a progressive die system. The method utilizes a thin strip of material as raw material and forms the nib on a side edge of the strip using multiple progressive dies. A first die stamps out a finger in the edge of the strip in a vertical stamping operation. A second die is then propelled horizontally into the terminal end of the finger to flatten the finger into a mounting shoulder and a small nib on the center of the mounting shoulder. A third die then blanks out the desired piece from the strip in another vertical stamping operation. The resulting piece is thus separated from the strip with the nib completely formed thereon.
In the case of the preferred embodiment illustrated herein, the desired part is a J-shaped earring back. The J-shaped back is assembled with a lever to form a completed pierced earring back. In further production, a finding, such as a stone setting, or an ornamental ball, is aligned adjacent to the mounting shoulder and fused together with the mounting shoulder to form a finished earring. For example, the fusion nib is aligned with an ornamental ball, and a current is applied across the aligned pieces. During arcing, the current flows directly through the fusion nib as a path of least resistance to the ball, or vice-versa. The nib instantaneously disintegrates and reforms as a weld between the mounting shoulder and the surface of the ball.
One very important advantage to the present invention is that it is not necessarily limited to the jewelry industry. The same method can also be used to form nibs on other larger parts. Because the method is a progressive stamping method, and uses strip feed material, the process is easily automated and inexpensive.
Accordingly, among the objects of the instant invention are: the provision of a simple and effective method of forming a fusion nib on small parts; the provision of a method of forming a fusion nib comprising the progressive stamping of a strip of feed material; the provision of a method of forming a fusion nib wherein the nib is formed in the side edge of the material using simple stamping dies.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.